Switching between watches or other accessories

A method performed on an electronic device that is associated with multiple wearable accessories, the method comprising:

• scanning for one or more on-body states from one or more associated accessories;
• determining, based on a difference in on-body states, that a switch between accessories has occurred, the switch being to a second accessory from a first accessory;
• and
• transmitting synchronization data to the second accessory in response to determining that the second accessory has established a communication connection for data exchange with the electronic device.

A data processing system comprising:

• memory to store instructions;
• one or more processors to execute instructions, wherein the instructions cause the one or more processors to perform operations comprising:
• scanning for one or more on-body states from one or more associated accessories;
• determining, based on a difference in on-body states, that a switch between accessories has occurred, the switch being to a second accessory from a first accessory;
• starting a timer in response to determining that the switch between accessories has occurred;
• ceasing, during a period of time before the timer expires, scanning for on-body states of other accessories;
• determining, during the period of time before the timer expires, whether the second accessory has established a communication connection for data exchange with an electronic device;
• and
• transmitting synchronization data to the second accessory in response to determining that the second accessory has established the communication connection for data exchange with the electronic device.